It was long ago but as I recall, I used jewler's polish grit mixed with concentrated antifreeze -- no water -----
Polish the crystal on a flat piece of glass.
My tube is 3' long - glass in glass. PVC is too flexible as I recall. I still have that tube with flex mounts for the lenses.

HMike

I looked on Ebay for commercial salt windows, but could not find any.

You mentioned PVC. Had you been able to use PVC, would you have used it for the water jacket only, or would you have tried to use it for the actual laser tube?

How long ago was this? Did you buy commercial pre-mix, or did you mix the gas yourself? Would you be interested in selling any of your optics (like the focusing lenses or OC)?

Jarrod --
I never used PVC for my old CO2 laser. It is all glassware. I wanted to see the plasma -- It's pink! I mixed my own gas -- He, N2, CO2.

I found 2 sealed NaCl unpolished windows. ~ 1" Dia x 0.2" thick.
I don't remember the what the 2 ZnSe "reflectors" are for sure but one is a total reflector I think and one is marked 94% transmissive. 0.75" Dia x 0.080" thick. Made by II-VI.

Jarrod --
I never used PVC for my old CO2 laser. It is all glassware. I wanted to see the plasma -- It's pink! I mixed my own gas -- He, N2, CO2.

I found 2 sealed NaCl unpolished windows. ~ 1" Dia x 0.2" thick.
I don't remember the what the 2 ZnSe "reflectors" are for sure but one is a total reflector I think and one is marked 94% transmissive. 0.75" Dia x 0.080" thick. Made by II-VI.

HMike

I ask about the PVC because you said "My tube is 3' long - glass in glass. PVC is too flexible as I recall.", which indicates to me that you at least considered the use of PVC for part of your construction. I plan to fabricate a water jacket using a fluorescent tube shield (example here)....